S1416 Medicaid Expansion Is Associated with Decreased Gastric Cancer Incidence

Abstract

Introduction: Individuals in Medicaid expanded states have increased access to treatment for medical conditions and other health care resources, including preventive healthcare. Esophageal and gastric cancer are associated with several modifiable risk factors (i.e. smoking, drinking, obesity, Helicobacter pylori infection). The impact of Medicaid expansion on gastric and esophageal cancer incidence and mortality remains uninvestigated. Methods: We evaluated the association between Medicaid expansion and gastric and esophageal cancer incidence and mortality in adults aged 25-64. This study employed an observational design using a difference-in-differences method with state level data from 31 states (given the availability of complete data), from 2010 – 2017. Annual, age-adjusted gastric and esophageal incidence and mortality rates, from the CDC Wonder Database, were analyzed and were accounted for by ICD-O-3 and ICD-10, respectively. Rates were adjusted for gender, race, poverty, median household income, unemployment, insurance, smoking, alcohol consumption, diabetes mellitus, obesity, and number of physicians per 100,000 population. Results: In expansion states, median (IQR) gastric cancer incidence was unchanged: from 4.6 (4.2-5.2) to 4.6 (4.1-5.4) per 100,000 population from the pre-expansion to post-expansion period. There was an increase in median (IQR) gastric cancer incidence among non-expansion states, from 4.6 (4.2-5.0) to 4.8 (4.3-5.1) per 100,000 from pre- to post-expansion. There was no considerable change in gastric cancer mortality and esophageal cancer incidence and mortality pre- and post- expansion. Adjusted analyses demonstrate that expansion states had significantly fewer new cases of gastric cancer: -1.6 (95% CI: 0.2-3.5; P = .08) per 1,000,000 persons per year. No significant association was seen between Medicaid expansion and gastric cancer mortality (0.46 [95% CI: -0.08-0.17; P = .46]) and esophageal cancer incidence (0.8 [95% CI: -0.08- 0.24; P = .33]) and mortality (1.0 [95% CI: -0.06-0.26; P = 0.21]) in multivariable analyses. Annual adjusted medians for gastric and esophageal cancer mortality and incidence are shown in Figure 1. Conclusion: States that adopted Medicaid expansion saw a decrease in gastric cancer incidence among adults aged 25-64 when compared to states that did not expand Medicaid. Though several factors may influence gastric cancer incidence, this association is important to consider during health policy negotiations.Figure 1.: Annual distribution of age-adjusted gastric and esophageal cancer incidence and mortality rates pre- and post- Medicaid expansion.Table 1.: Comparison of sociodemographic and clinical characteristics of Expansion Vs Non-Expansion States based on 2010 data.